Find the real values of x and y for which:
$(x+i y)(3-2 i)=(12+5 i)$
$x(3-2 i)+i y(3-2 i)=12+5 i$
$\Rightarrow 3 x-2 i x+3 i y-2 i^{2} y=12+5 i$
$\Rightarrow 3 x+i(-2 x+3 y)-2(-1) y=12+5 i\left[\because i^{2}=-1\right]$
$\Rightarrow 3 x+i(-2 x+3 y)+2 y=12+5 i$
$\Rightarrow(3 x+2 y)+i(-2 x+3 y)=12+5 i$
Comparing the real parts, we get
$3 x+2 y=12 \ldots(i)$
Comparing the imaginary parts, we get
$-2 x+3 y=5 \ldots$ (ii)
Solving eq. (i) and (ii) to find the value of x and y
Multiply eq. (i) by 2 and eq. (ii) by 3, we get
$6 x+4 y=24 \ldots$ (iii)
$-6 x+9 y=15 \ldots$ (iv)
Adding eq. (iii) and (iv), we get
$6 x+4 y-6 x+9 y=24+15$
$\Rightarrow 13 y=39$
$\Rightarrow y=3$
Putting the value of y = 3 in eq. (i), we get
$3 x+2(3)=12$
$\Rightarrow 3 x+6=12$
$\Rightarrow 3 x=12-6$
$\Rightarrow 3 x=6$
$\Rightarrow x=2$
Hence, the value of x = 2 and y = 3